Last Modified: 05-13-2024 |
6.11:8.1.0 |
Doc ID: RM100000001GKC7 |
Model Year Start: 2020 |
Model: Corolla |
Prod Date Range: [01/2019 - 11/2022] |
Title: 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: Fuel Pump Control Circuit; 2020 - 2023 MY Corolla [01/2019 - 11/2022] |
Fuel Pump Control Circuit
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DESCRIPTION
When the engine is cranked, the ST relay drive signal output from the ignition or starter switch assembly*1 or certification ECU (smart key ECU assembly)*2 is input into the STA terminal of the ECM, and the NE signal generated by the crank position sensor is also input into the NE+ terminal. The ECM interprets that the engine is cranked, and turns transistor Tr1 in the ECM internal circuit on. Current flows to the C/OPN relay by turning Tr1 on. Then, the fuel pump operates.
While the NE signal is input into the ECM with the engine running, the ECM turns Tr1 on continuously.
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*1: w/o Smart Key System
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*2: w/ Smart Key System
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
1.
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PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP/SPEED)
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(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump/Speed.
Powertrain > Engine and ECT > Active Test
Tester Display
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Control the Fuel Pump / Speed
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(e) Check whether the fuel pump operating sound occurs when performing the Active Test on the Techstream.
Result
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Proceed to
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Fuel pump operating sound does not occur
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A
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Fuel pump operating sound occurs
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B
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A
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2.
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CHECK TERMINAL VOLTAGE (POWER SOURCE OF C/OPN RELAY)
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(a) Remove the C/OPN relay from the No. 1 engine room relay block and No. 1 junction block assembly.
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*1
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No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
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*2
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C/OPN Relay
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(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
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Condition
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Specified Condition
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1 (C/OPN relay) - Body ground
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Ignition switch ON
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11 to 14 V
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OK
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(a) Inspect the C/OPN relay.
Click here
NG |
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REPLACE C/OPN RELAY
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OK
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4.
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CHECK HARNESS AND CONNECTOR (C/OPN RELAY - ECM)
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(a) Remove the C/OPN relay from the No. 1 engine room relay block and No. 1 junction block assembly.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
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Condition
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Specified Condition
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2 (C/OPN relay) - A46-41 (FC)
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Always
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Below 1 Ω
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2 (C/OPN relay) or A46-41 (FC) - Body ground and other terminals
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Always
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10 kΩ or higher
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NG |
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REPAIR OR REPLACE HARNESS OR CONNECTOR
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OK
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5.
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CHECK HARNESS AND CONNECTOR (C/OPN RELAY - FUEL PUMP)
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(a) Remove the C/OPN relay from the No. 1 engine room relay block and No. 1 junction block assembly.
(b) Disconnect the fuel pump connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
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Condition
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Specified Condition
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3 (C/OPN relay) - O44-4 (B)
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Always
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Below 1 Ω
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3 (C/OPN relay) or O44-4 (B) - Body ground and other terminals
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Always
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10 kΩ or higher
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NG |
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REPAIR OR REPLACE HARNESS OR CONNECTOR
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OK
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6.
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CHECK HARNESS AND CONNECTOR (FUEL PUMP - BODY GROUND)
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(a) Disconnect the fuel pump connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
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Condition
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Specified Condition
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O44-5 (E) - Body ground
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Always
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Below 1 Ω
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NG |
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REPAIR OR REPLACE HARNESS OR CONNECTOR
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OK
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(a) Inspect the fuel pump.
Click here
HINT:
Perform "Inspection After Repair" after replacing the fuel pump.
Click here
OK
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8.
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CHECK HARNESS AND CONNECTOR (EFI-MAIN RELAY - C/OPN RELAY)
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(a) Remove the EFI-MAIN relay and C/OPN relay from the No. 1 engine room relay block and No. 1 junction block assembly.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
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Condition
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Specified Condition
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3 (EFI-MAIN relay) - 5 (C/OPN relay)
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Always
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Below 1 Ω
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3 (EFI-MAIN relay) or 5 (C/OPN relay) - Body ground and other terminals
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Always
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10 kΩ or higher
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NG |
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REPAIR OR REPLACE HARNESS OR CONNECTOR
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9.
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CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - C/OPN RELAY)
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(a) Disconnect the No. 1 integration relay connector.
(b) Remove the C/OPN relay from the No. 1 engine room relay block and No. 1 junction block assembly.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
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Condition
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Specified Condition
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1A-9 - 1 (C/OPN relay)
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Always
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Below 1 Ω
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1A-9 or 1 (C/OPN relay) - Body ground and other terminals
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Always
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10 kΩ or higher
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NG |
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REPAIR OR REPLACE HARNESS OR CONNECTOR
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10.
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READ VALUE USING TECHSTREAM (STARTER SIGNAL)
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(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Starter Signal.
Powertrain > Engine and ECT > Data List
Tester Display
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Starter Signal
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(e) Check the result when the ignition switch is ON and the engine starts.
OK:
Condition
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Starter Signal
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Ignition switch ON
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OFF
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Engine started
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ON
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OK
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11.
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READ VALUE USING TECHSTREAM (ENGINE SPEED)
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(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Speed.
Powertrain > Engine and ECT > Data List
Tester Display
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Engine Speed
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(e) Read the values displayed on the Techstream while cranking.
OK:
Values are displayed continuously.
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